A typical flash memory device may comprise a memory array that includes a large number of non-volatile memory cells arranged in row and column fashion. In recent years, vertical memory, such as three-dimensional (3D) memory has been developed in various forms, such as NAND, cross-point, or the like. A 3D flash memory array may include a plurality of memory cells stacked over one another. Each group of memory cells may share a plurality of access lines, known as wordlines (WLs) and bitlines (BLs).
In a memory device fabrication, a memory array including access lines (e.g., wordlines) may be etched in a memory region of a die, and connectivity with circuitry may be provided through an adjacent periphery region of a die. The memory array fabrication may include a number of operations, including filling gaps between the wordlines (or bitlines) etched in a die with a dielectric fill material, in order to provide desired structural integrity.